Orientation relationships of Mn0.75Ga0.25As crystallites on and within GaAs determined by scanning nano beam electron diffraction

• Published in: Crystal research and technology (1979) Vol. 52; no. 1
• Main Authors: Häusler, Ines, Moeck, Peter, Volz, Kerstin, Neumann, Wolfgang
• Format: Journal Article
• Language: English
• Published: 01.01.2017
• Subjects: (Mn,Ga)As crystallites; crystal phase determination; orientation mapping; scanning nano beam electron diffraction; STEM/TEM imaging
• ISSN: 0232-1300; 1521-4079
• DOI: 10.1002/crat.201600261

Mn0.75Ga0.25As crystallites, partially embedded on and fully embedded within a single crystalline matrix of GaAs formed during metal organic vapor phase epitaxy (MOVPE) of Mn‐rich (Mn,Ga)As on (001) oriented GaAs wafers. Phase and orientation analysis of these crystallites were performed with scanning nano beam electron diffraction (SNBED). The investigation of plan‐view specimens using a liquid nitrogen cooling stage enabled the phase and orientation analysis of partially embedded ferromagnetic α‐phase particles. In all specimens the following two orientation relationships (O) between the α‐phase particles and the GaAs matrix were determined: O1:[12¯.0]Mn0.75Ga0.25 As ||110 GaAs and 10.2Mn0.75Ga0.25 As || GaAs O2:[10.2]Mn0.75Ga0.25 As ||110 GaAs and 12¯.0Mn0.75Ga0.25 As || GaAs . The study of cross‐sectional specimens enabled the analysis of fully embedded crystallites. It could be unambiguously detected that a fully embedded crystallite has the structure of the atomically ordered monoclinic β´ phase. The β´ phase crystallite consists of two domains which are related in twin positions to each other. The orientation relations of the different particles are illustrated by color coded stereographic projections. Scanning nano beam electron diffraction was employed to determine the orientation relationships of different crystallographic phases of (Mn,Ga)As crystallites in a GaAs matrix. The orientation relationships are illustrated by means of corresponding color coded stereographic projections.